Most sensible explanation so far. It accounts for why they would be worried about hidden, automatic cameras much more than the ones regular tourists have, where you can see when they're taking a picture or getting a good video angle. Also, most tourists don't take pictures of what's going on behind the counter, so you can catch someone trying to overtly do that, but a hidden camera would make that harder to spot, leading management to be more paranoid about built-in cameras.
On top of that, "concern about the health department" has a much higher prior probability than "mafia collusion with major fast food chain".
What does strike me as odd is that it seems pretty likely that a McDonald's at tourist central would have to have a lot of pictures taken of it and in it and around it. It seems like that wouldn't even come close to being unusual.
Granted, not usually by someone with the camera literally attached to his head.
I thought I was saying the same thing: that yes, tourists are expected to be everywhere at the McDonald's, taking pictures, but if they start to do it in a strange way (i.e., target the "boring" stuff in the kitchen), or have stuff that looks like a hidden camera, then management may freak out.
On top of that, "concern about the health department" has a much higher prior probability than "mafia collusion with major fast food chain".